The Elio Engine

[Snick]

The reason you can gear it taller and run the engine at low-ish rpm's on the freeway is because the required road load is so low (very aerodynamic body, less tire rolling resistance, and lighter weight than even a small 4-wheeled car.)

 

[Ekh]

I think I saw 52hp @ 2,800rpm in the video.

I couldn't decode the screens well enough to see that. Which panel had the HP read-out?

 

[Ekh]

Welcome to ElioOwners.com glad you could join us! We have quite a few members from Ohio here.

We do not yet know the gearing. My guess is that EM and IAV have a good idea what it will be however they are likely waiting on pre-production vehicle testing to make a final determination on gearing.

As this vehicle is aimed at fuel efficiency I would not be surprised to see some stretched out gearing especially in 5th in order to maximize highway cruise efficiency. This engine is also of an undersquare design with a long stroke and narrow bore so it will not be a high revving engine and instead is more focused on low end torque.

The car is being optimized to produce 84 mpg at 65 mph (Per Jerome Vassallo, last summer). The extra long stroke (and consequent higher torque) of this custom-designed mill is what makes it possible to hold highway speed at non-thirsty RPMs. If you want to get up and go, change gears, and as the RPMs increase, the valves open at a different point, and off you go. But if you wind her up, the engine will be relatively much more thirsty than at the more leisurely RPMs.

I've never been quite clear on how the 2-step cam works, but I think I have the general proposition correct. I'm sure the experts here will correct me (gently, please) if I've got it mixed up.

 

[Ekh]

I made that same observation a few months ago .... I well remember when with 87 octane 8:1 ratios were about as good as it got .... back then I was told that these high compression ratings have been in use for a while by several manufactures .... I still don't understand exactly how it works but it apparently does

Precise ignition and valve timing; better stoichometric fuel mixtures.

 

[Ian442]

When Homer screws up its d'oh!

 

[JEBar]

Precise ignition and valve timing; better stoichometric fuel mixtures.

"stoichometric" .... had to look that one up ..o_O.. years ago we were told that going above 8:1 with 87 octane unleaded gasoline would result in knocking .... with still using 87 octane unleaded gasoline, I can see timing playing a big part

 

[Snick]

"stoichometric" .... had to look that one up ..o_O.. years ago we were told that going above 8:1 with 87 octane unleaded gasoline would result in knocking .... with still using 87 octane unleaded gasoline, I can see timing playing a big part

That may be for a really poorly designed engine.

Even cars as "new" as 1997 build date can tolerate 87 octane at compression ratios of 10.5:1. On a mountain drive in summer, higher octanes are advised.

The tolerance to lower octanes comes from better engineered combustion chambers and sensitive and fast responding knock sensing and timing controls.

 

[Johnny Acree]

Just wondering,,, After IAV finishes testing the engine, what comes next?

 

[JEBar]

That may be for a really poorly designed engine.

Even cars as "new" as 1997 build date can tolerate 87 octane at compression ratios of 10.5:1. On a mountain drive in summer, higher octanes are advised.

The tolerance to lower octanes comes from better engineered combustion chambers and sensitive and fast responding knock sensing and timing controls.

my limited knowledge goes back a bit further, to the mid '70's .... have been pretty much out of the loop since then

 

[Thomas Maule]

Just wondering,,, After IAV finishes testing the engine, what comes next?

I believe whats next is figuring out the exact mount points on an E model, and installing a whole unit (with probably a 2nd engine) to make sure there are no weird vibration issues, and then begin rolling off your test models for crash and road testing, ect...

now IAV is supposedly well into testing the engine... I am not sure how far exactly, but they did not just start with the release of that video... I would not be surprised if there is an almost complete E model sitting somewhere waiting on some more finalization's...